This book encompasses a detailed account of chromosome biology of fourteen species of the South Indian midges with respect to mitotic, meiotic and polytene chromosome organization. Studies on polytene chromosomes have been extremely important in the field of cytogenetics and are used as a handy model for studying structural and functional organization of eukaryotic chromosomes. Polytene banding sequences are used as a parameter in majority of chromosomal evolution and species differentiation studies. Chironomids are very sensitive to environmental stress and the response of genome to environmental stress can be well defined and monitored due to the presence of polytene chromosomes and used as a bio-monitoring model for eco-toxicological tests. The chromosomal study of south Indian chironomids helps in further exploring the South Indian fauna with reference to Karyotypic analysis, inversion polymorphism and for studying the impact of contaminants and evaluating their significance in fresh water ecosystem.